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  • Blind spots-- human eyes have a blind spot when the optic nerve exits the back in the eye.

  • This area has no light receptors because the nerve is in the way

  • you can find your blind spot with this test.

  • Look at the red cross on the left with your right eye

  • closing your left eye, move your head slowly closer and further away

  • "So weird" at a certain distance the blue dot on the right will disappear

  • pause if you need to, you've just found your blind spot

  • After images, stare at the white dot in the center of the image and try not to blink.

  • your eyes have three types of cones or color receptors

  • red, green and blue.

  • After images disappear when you stare at a particular color for too long

  • and those color receptors get tired.

  • so when you suddenly switch to looking at a black and white image

  • those tired receptors aren't working as well

  • This leaves an afterimage of the reverse colors.

  • See your veins!

  • Blood vessels and veins feed the photosensitive cells in your eye to keep them alive

  • These blood vessels cast shadows on your retina

  • Here's how you can see those veins.

  • Poke a small hole in a post it note or piece of paper

  • hold that against a bright white background like your computer screen

  • look to the hole while shaking the post-it slightly

  • you should see a shadowy network online sort of like the veins a leaf

  • these are the veins in your eye. Gross...

  • dominant eyes

  • Most people have a dominant eyes, meaning that one eye gives more priority information than the other

  • Eighty percent of people are right eye dominant

  • See which is your dominant eye.

  • Make a triangle between your thumbs and forefingers

  • With both eyes open, look at an object several feet away

  • Center the object inside the triangle, close one eye and then the other.

  • Your dominant eye will look like this

  • and your non-dominant eye will look like this.

  • It's almost visionary.. see what "I" did there

Blind spots-- human eyes have a blind spot when the optic nerve exits the back in the eye.

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